1. Field of the Invention
The present invention relates to a recording head and a recording apparatus, and more particularly, to a recording head (e.g., print head) capable of discharging two or more types of ink droplets and a recording apparatus (e.g., printer) to control operations of the recording head.
2. Description of the Related Art
In general, inkjet recording apparatuses have low noises and compact bodies, and require relatively low running costs. Accordingly, many inkjet recording apparatuses are widely used as ordinary printers or copying machines.
A thermal energy type recording apparatus can generate bubbles to discharge ink droplets. In such an inkjet recording apparatus, to stably discharge the ink from a recording head, the recording head is equipped with a memory unit that can store the information relating to head characteristics (refer to Japanese Patent Application Laid-open No. 7-52388).
Based on the stored information, the inkjet recording apparatus can select optimum head driving conditions (i.e., driving parameters) from information relating to driving conditions which are prepared beforehand in the inkjet recording apparatus.
Then, the inkjet recording apparatus can control and drive the recording head based on the selected driving conditions with reference to an ambient temperature and/or a recording head temperature.
In general, the manufacturing of discharge elements of a recording head and wiring for the discharge elements is not free from dispersion or errors. The driving conditions for each recording head should be determined considering the dispersion or errors in the manufacturing. The built-in memory unit of the recording head stores information relating to compensation of the driving conditions.
After a recording head is installed on an inkjet recording apparatus, the inkjet recording apparatus can read compensation information from the built-in memory unit of the recording head and can control an operation of the recording head based on the readout information.
Furthermore, recent inkjet recording apparatuses are configured to discharge two or more types of ink droplets, to realize both high-speed printing and high-quality (e.g., photographic quality) printing. For example, a recording head (especially, a color head) includes high-speed printing nozzles that can discharge 10-5 pl (pico-liter) ink droplets and high-quality printing nozzles that can discharge 4-1 pl ink droplets.
However, as described above, according to the conventional inkjet recording apparatus, the built-in memory unit of the recording head stores all of the required information relating to driving conditions that are differentiated for two or more types of ink discharge amounts or for a plurality of colors. Thus, the built-in memory unit of the recording head must have a large memory capacity. As a result, the cost of a recording head increases.
Furthermore, the above-described built-in memory unit of the recording head is, for example, a fuse ROM. The fuse ROM can store desired information based on a combination of cutoff fuses and non-cut fuses.
Therefore, the fuse ROM requires time-consuming processing for cutting fuses in the manufacturing of a recording head. Accordingly, if the amount of stored information increases, the time required for cutting processing will increase correspondingly. As a result, the manufacturing time per recording head becomes longer.